UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

Amendment No. 1

to

FORM
20-F

(Mark One)



| ̈ | REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | ----------------------------------------------------------------------------------------------

OR



|x | ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | ------------------------------------------------------------------------------------

For the fiscal year ended June 30, 2012

OR



| ̈ | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | ----------------------------------------------------------------------------------------

For the transition period from
         to

OR



| ̈ | SHELL COMPANY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
|- | -------------------------------------------------------------------------------------------

Date of event requiring this shell company report

Commission file number 001-35428

Prima BioMed Ltd

(Exact name of Registrant as specified in its charter

and translation of Registrants name into English)

Australia

(Jurisdiction of incorporation or organization)

Level 7, 151 Macquarie Street, Sydney 2000, New South Wales, Australia

(Address of principal executive offices)

Matthew Lehman, Chief Executive Officer

Level 7, 151 Macquarie Street,
Sydney, 2000 New South Wales, Australia

Phone +61 (0)2 9276 1224 Fax:+61 (0)2 9276 1284

Securities registered or to be registered pursuant to Section 12(b) of the Act.



|                    |  |  |  |                                                                                                                                    
|------------------- |  |  |  | -----------------------------------------------------------------------------------------------------------------------------------
|Title of each class |  |  |  | Name of each exchange on which registered                                                                                          
|                    |  | 
|Ordinary Shares     |  |  |  | The NASDAQ Stock Market LLC (in connection with
the listing for trading of American Depositary Shares representing Ordinary Shares)

Securities registered or to be registered pursuant to Section 12(g) of the Act. None

Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act. None

Indicate the number of outstanding shares of each of the issuers classes of capital or common stock as of the close of the period covered by the
Annual Report.

The number of ordinary shares, as of June 30, 2012 1,066,063,388

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.   ̈ Yes  x No

If this report is
an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of
1934.   ̈ Yes  x No

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for
such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.  x Yes   ̈ No

Indicate by check mark whether the registrant has submitted electronically and posted on
its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was
required to submit and post such files).   ̈ Yes   ̈ No

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of accelerated filer and large accelerated filer in
Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated
filer   ̈                 Accelerated
filer   ̈                 Non-accelerated filer  x

Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:



|             |  |                                                                                                          |  |         
|------------ |  | -------------------------------------------------------------------------------------------------------- |  | --------
|U.S. GAAP   ̈ |  | International Financial Reporting Standards as issued by the International Accounting Standards Board  x |  | Other   ̈

If Other has been checked in response to the previous question, indicate by check mark which financial
statement item the registrant has elected to follow.   ̈ Item 17   ̈ Item 18

If this is an Annual Report, indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).   ̈ Yes  x No









---

EXPLANATORY NOTE

This Amendment No. 1 to Form 20-F is filed solely to refile Exhibit 4.5 hereto.



---

PART III



|ITEM 19. | EXHIBITS
|-------- | --------

The following
exhibits are filed as part of this Annual Report on Form 20-F:



|        |  |                                                                                                                                                                                                                  |  |                           |  |            |  |         |  |         
|------- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | ------------------------- |  | ---------- |  | ------- |  | --------
|        |  |                                                                                                                                                                                                                  |  | Incorporated by Reference
|Exhibit |  | Description                                                                                                                                                                                                      |  | Schedule/Form             |  | FileNumber |  | Exhibit |  | FileDate
|1.1     |  | Constitution of Registrant                                                                                                                                                                                       |  | 20-F                      |  | 001-35428  |  | 1.1     |  | 2/13/12 
|2.1     |  | Form of Deposit Agreement between Prima BioMed, The Bank of New York Mellon, as Depositary, and owners and holders from time to time of ADSs issued thereunder, including the Form of
American Depositary Shares |  | 20-F                      |  | 001-35428  |  | 2.1     |  | 4/2/12  
|4.1     |  | Convertible Loan Agreement between Prima BioMed and SpringTree Global Opportunities Fund, LP, dated July 20, 2009                                                                                                |  | 20-F                      |  | 001-35428  |  | 4.1     |  | 2/13/12 
|4.2     |  | Amendment Deed between Prima BioMed and SpringTree Special Global Opportunities Fund, LP, dated January 10, 2011                                                                                                 |  | 20-F                      |  | 001-35428  |  | 4.2     |  | 2/13/12 
|4.3^    |  | Master Services Agreement between Prima BioMed and Cell Therapies Pty Ltd, dated April 1, 2011                                                                                                                   |  | 20-F                      |  | 001-35428  |  | 4.3     |  | 10/3/12 
|4.4*    |  | Technology License Agreement, among Prima BioMed, Cancer Vac Pty Ltd, Austin Research Institute and Ilexus Pty Ltd, dated May 31, 2001, as amended by Deed of Variation, dated August
24, 2005                   |  | 20-F                      |  | 001-35428  |  | 4.5     |  | 2/13/12 
|4.5^#   |  | Cooperation Agreement between Prima BioMed GmbH and Fraunhofer-Gesellschaft zur Forderungder angewandaten Forschung e.V., dated July 4, 2012                                                                     |  |                           |  |            |  |         |  |         
|4.6*    |  | License and Development Agreement among Prima BioMed, Cancer Vac Pty Ltd and Biomira, Inc., dated March 9, 2004, as amended by Deed of Variation of License and Development
Agreement, dated February 2007       |  | 20-F                      |  | 001-35428  |  | 4.7     |  | 2/13/12 
|4.7*    |  | Collaborative Research Agreement between Prima BioMed and NewSouth Innovations Pty Limited, dated December 17, 2009                                                                                              |  | 20-F                      |  | 001-35428  |  | 4.8     |  | 2/13/12 
|4.8*    |  | Services Agreement between Prima BioMed and Progenitor Cell Therapy LLC, dated May 13, 2009, as amended November 10, 2009 and March 18, 2010                                                                     |  | 20-F                      |  | 001-35428  |  | 4.11    |  | 2/13/12 
|4.9+    |  | Prima BioMed Employee Share Option Plan                                                                                                                                                                          |  | 20-F                      |  | 001-35428  |  | 4.12    |  | 2/13/12 
|4.10+   |  | Prima BioMed Global Employee Share Option Plan                                                                                                                                                                   |  | 20-F                      |  | 001-35428  |  | 4.10    |  | 10/3/12 
|4.11+   |  | Employment Agreement between Prima BioMed and Martin Rogers, effective January 1, 2011                                                                                                                           |  | 20-F                      |  | 001-35428  |  | 4.13    |  | 2/13/12 
|4.12+   |  | Employment Agreement between Prima BioMed and Neil Frazer, effective March 1, 2010                                                                                                                               |  | 20-F                      |  | 001-35428  |  | 4.14    |  | 2/13/12 
|4.13+   |  | Employment Agreement between Prima BioMed and Matthew Bryson Lehman, effective February 1, 2010                                                                                                                  |  | 20-F                      |  | 001-35428  |  | 4.15    |  | 2/13/12 
|4.14+   |  | Employment Agreement between Prima BioMed and Sharron Gargosky, dated June 1, 2011                                                                                                                               |  | 20-F                      |  | 001-35428  |  | 4.14    |  | 10/3/12 
|4.15+   |  | Employment Agreement between Prima BioMed and Marc Voigt, effective July 1, 2012                                                                                                                                 |  | 20-F                      |  | 001-35428  |  | 4.15    |  | 10/3/12 
|4.16+   |  | Employment Agreement between Prima BioMed and Ian Bangs, effective February 11, 2011                                                                                                                             |  | 20-F                      |  | 001-35428  |  | 4.18    |  | 2/13/12 



---

|        |  |                                                                                                               |  |                           |  |            |  |         |  |         
|------- |  | ------------------------------------------------------------------------------------------------------------- |  | ------------------------- |  | ---------- |  | ------- |  | --------
|        |  |                                                                                                               |  | Incorporated by Reference
|Exhibit |  | Description                                                                                                   |  | Schedule/Form             |  | FileNumber |  | Exhibit |  | FileDate
|12.1#   |  | Certification of Chief Executive Officer as required by Rule 13a-14(a) of the Securities Exchange Act of 1934 |  |                           |  |            |  |         |  |         
|12.2#   |  | Certification of Chief Financial Officer as required by Rule 13a-14(a) of the Securities Exchange Act of 1934 |  |                           |  |            |  |         |  |         
|13.1    |  | Certification of Chief Executive Officer as required by Rule 13a-14(b) of the Securities Exchange Act of 1934 |  | 20-F                      |  | 001-35428  |  | 13.1    |  | 10/3/12 
|13.2    |  | Certification of Chief Financial Officer as required by Rule 13a-14(b) of the Securities Exchange Act of 1934 |  | 20-F                      |  | 001-35428  |  | 13.2    |  | 10/3/12 
|16.1    |  | Letter regarding change in certifying accountant                                                              |  | 20-F                      |  | 001-35428  |  | 16.1    |  | 10/3/12 



|* | Confidential treatment has been granted with respect to certain portions of this exhibit. Omitted portions have been submitted separately with the U.S. Securities and
Exchange Commission.
|- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|^ | Confidential treatment has been requested with respect to certain portions of this exhibit. Omitted portions have been submitted separately with the U.S. Securities and
Exchange Commission.
|- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|+ | Indicates management contract or compensatory plan.
|- | ---------------------------------------------------

|# | Filed herewith.
|- | ---------------

In accordance with SEC Release
Nos. 33-8238 and 34-47986, Final Rule: Managements Reports on Internal Control Over Financial Reporting and Certification of Disclosure in Exchange Act Periodic Reports, and the instructions to Form 20-F, the certifications furnished in
Exhibits 13.1 and 13.2 were deemed to accompany the Annual Report on Form 20-F and are not deemed filed for purpose of Section 18 of the Exchange Act. Such certifications will not be deemed to be incorporated by reference into
any filing under the Securities Act or the Exchange Act, except to the extent that we specifically incorporate it by reference.





---

SIGNATURES

The registrant hereby certifies that it meets all of the requirements for filing on Form 20-F and that it has duly caused and authorized the undersigned to sign this Annual Report on its behalf.



PRIMA BIOMED LTD/s/ Matthew LehmanBy: Matthew Lehman
Title: Chief Executive Officer


Date: December 3, 2012



---

EXHIBIT INDEX



|        |  |                                                                                                                                                                                                                  |  |                           |  |            |  |         |  |         
|------- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | ------------------------- |  | ---------- |  | ------- |  | --------
|        |  |                                                                                                                                                                                                                  |  | Incorporated by Reference
|Exhibit |  | Description                                                                                                                                                                                                      |  | Schedule/Form             |  | FileNumber |  | Exhibit |  | FileDate
|1.1     |  | Constitution of Registrant                                                                                                                                                                                       |  | 20-F                      |  | 001-35428  |  | 1.1     |  | 2/13/12 
|2.1     |  | Form of Deposit Agreement between Prima BioMed, The Bank of New York Mellon, as Depositary, and owners and holders from time to time of ADSs issued thereunder, including the Form of
American Depositary Shares |  | 20-F                      |  | 001-35428  |  | 2.1     |  | 4/2/12  
|4.1     |  | Convertible Loan Agreement between Prima BioMed and SpringTree Global Opportunities Fund, LP, dated July 20, 2009                                                                                                |  | 20-F                      |  | 001-35428  |  | 4.1     |  | 2/13/12 
|4.2     |  | Amendment Deed between Prima BioMed and SpringTree Special Global Opportunities Fund, LP, dated January 10, 2011                                                                                                 |  | 20-F                      |  | 001-35428  |  | 4.2     |  | 2/13/12 
|4.3^    |  | Master Services Agreement between Prima BioMed and Cell Therapies Pty Ltd, dated April 1, 2011                                                                                                                   |  | 20-F                      |  | 001-35428  |  | 4.3     |  | 10/3/12 
|4.4*    |  | Technology License Agreement, among Prima BioMed, Cancer Vac Pty Ltd, Austin Research Institute and Ilexus Pty Ltd, dated May 31, 2001, as amended by Deed of Variation, dated August
24, 2005                   |  | 20-F                      |  | 001-35428  |  | 4.5     |  | 2/13/12 
|4.5^#   |  | Cooperation Agreement between Prima BioMed GmbH and Fraunhofer-Gesellschaft zur Forderungder angewandaten Forschung e.V., dated July 4, 2012                                                                     |  |                           |  |            |  |         |  |         
|4.6*    |  | License and Development Agreement among Prima BioMed, Cancer Vac Pty Ltd and Biomira, Inc., dated March 9, 2004, as amended by Deed of Variation of License and Development
Agreement, dated February 2007       |  | 20-F                      |  | 001-35428  |  | 4.7     |  | 2/13/12 
|4.7*    |  | Collaborative Research Agreement between Prima BioMed and NewSouth Innovations Pty Limited, dated December 17, 2009                                                                                              |  | 20-F                      |  | 001-35428  |  | 4.8     |  | 2/13/12 
|4.8*    |  | Services Agreement between Prima BioMed and Progenitor Cell Therapy LLC, dated May 13, 2009, as amended November 10, 2009 and March 18, 2010                                                                     |  | 20-F                      |  | 001-35428  |  | 4.11    |  | 2/13/12 
|4.9+    |  | Prima BioMed Employee Share Option Plan                                                                                                                                                                          |  | 20-F                      |  | 001-35428  |  | 4.12    |  | 2/13/12 
|4.10+   |  | Prima BioMed Global Employee Share Option Plan                                                                                                                                                                   |  | 20-F                      |  | 001-35428  |  | 4.10    |  | 10/3/12 
|4.11+   |  | Employment Agreement between Prima BioMed and Martin Rogers, effective January 1, 2011                                                                                                                           |  | 20-F                      |  | 001-35428  |  | 4.13    |  | 2/13/12 
|4.12+   |  | Employment Agreement between Prima BioMed and Neil Frazer, effective March 1, 2010                                                                                                                               |  | 20-F                      |  | 001-35428  |  | 4.14    |  | 2/13/12 
|4.13+   |  | Employment Agreement between Prima BioMed and Matthew Bryson Lehman, effective February 1, 2010                                                                                                                  |  | 20-F                      |  | 001-35428  |  | 4.15    |  | 2/13/12 
|4.14+   |  | Employment Agreement between Prima BioMed and Sharron Gargosky, dated June 1, 2011                                                                                                                               |  | 20-F                      |  | 001-35428  |  | 4.14    |  | 10/3/12 
|4.15+   |  | Employment Agreement between Prima BioMed and Marc Voigt, effective July 1, 2012                                                                                                                                 |  | 20-F                      |  | 001-35428  |  | 4.15    |  | 10/3/12 
|4.16+   |  | Employment Agreement between Prima BioMed and Ian Bangs, effective February 11, 2011                                                                                                                             |  | 20-F                      |  | 001-35428  |  | 4.18    |  | 2/13/12 
|12.1#   |  | Certification of Chief Executive Officer as required by Rule 13a-14(a) of the Securities Exchange Act of 1934                                                                                                    |  |                           |  |            |  |         |  |         
|12.2#   |  | Certification of Chief Financial Officer as required by Rule 13a-14(a) of the Securities Exchange Act of 1934                                                                                                    |  |                           |  |            |  |         |  |         
|13.1    |  | Certification of Chief Executive Officer as required by Rule 13a-14(b) of the Securities Exchange Act of 1934                                                                                                    |  | 20-F                      |  | 001-35428  |  | 13.1    |  | 10/3/12 
|13.2    |  | Certification of Chief Financial Officer as required by Rule 13a-14(b) of the Securities Exchange Act of 1934                                                                                                    |  | 20-F                      |  | 001-35428  |  | 13.2    |  | 10/3/12 
|16.1    |  | Letter regarding change in certifying accountant                                                                                                                                                                 |  | 20-F                      |  | 001-35428  |  | 16.1    |  | 10/3/12 



|* | Confidential treatment has been granted with respect to certain portions of this exhibit. Omitted portions have been submitted separately with the U.S. Securities and
Exchange Commission.
|- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



---

|^ | Confidential treatment has been requested with respect to certain portions of this exhibit. Omitted portions have been submitted separately with the U.S. Securities and
Exchange Commission.
|- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

|+ | Indicates management contract or compensatory plan.
|- | ---------------------------------------------------

|# | Filed herewith.
|- | ---------------

In accordance with SEC Release
Nos. 33-8238 and 34-47986, Final Rule: Managements Reports on Internal Control Over Financial Reporting and Certification of Disclosure in Exchange Act Periodic Reports, and the instructions to Form 20-F, the certifications furnished in
Exhibits 13.1 and 13.2 hereto were deemed to accompany the Annual Report on Form 20-F and are not deemed filed for purpose of Section 18 of the Exchange Act. Such certifications will not be deemed to be incorporated by
reference into any filing under the Securities Act or the Exchange Act, except to the extent that we specifically incorporate it by reference.